Ok, their are lots of stuck fermentation post, but non I can find are answering my question... So here it is.

I have had a 1.050 OG ale fermenting at 64-65 degrees with Ringwood Wyeast for 15 days. I judge most of my brews primary fermentation progress by air lock activity, and most are at about to 3-4 bubbles a minute within a week. With this beer however, I am still bubbling 4 times a minute at day 15, and have been around that rate for a couple days.

I am planning on just giving it a few more days and hope to complete fermentation. But 15 days seem a little long, and I have heard some iffy things about ringwood. So I was just wondering if I am ok, or may I be having a problem?

If your yeast did not start fermenting within 24 hours from pitching then it must have started later to still be going on day 15. Did you pitch cold or at 80 F.

How much yeast was used? Starter?

All my ales vigorus fermentations are complete within 4 days and the yeast start right away. Some liquid yeast starters start to ferment within 8 hours. I aerate with oxygen or shake the crap out of the carboy and I pitch ales at 75 to 80 F. Once I see fermentation starting I lower the temperature to 63 to 65F.